1. Field of the Invention
This invention relates generally to semiconductor devices and manufacturing processes, and more particularly, to formation of a bottom antireflective coating (BARC) in a semiconductor structure.
2. Discussion of the Related Art
In semiconductor technology it is well-known to provide a bottom antireflective coating (BARC) on a surface beneath a layer of photoresist, to aid in the patterning of images. The BARC cuts down on light scattering into the resist, which helps in defining images. The BARC also minimizes standing waves effects and improves image contrast.
In order to achieve these advantages, the BARC must be relatively defect free. Such a uniform BARC would provide a more uniform reflectivity, in turn leading to better photolithographic pattern resolution.
Using a normal spinon technique to apply a BARC on a substrate can result in numerous defects therein in the form of variations in thickness, leading to the problems described above.
Therefore, what is needed is a method for forming a low defect BARC layer, so that manufacturing efficiency is increased.
In the present method, rather than applying a BARC directly onto a substrate, a primer, for example, vapor deposited hexamethyldisilazane (HMDS) along with a small amount of trimethylsilyldiethylamine (TMSDEA) as an additive, is vapor deposited on the substrate, and the BARC is formed on the primer. Then a layer of photoresist may be formed over the BARC. The inclusion of the primer layer results in a low defect BARC, in fact eliminating defects due to variations in thickness, so that the BARC provide uniform reflectivity to in turn provide improved photolithographic pattern resolution
The present invention is better understood upon consideration of the detailed description below, in conjunction with the accompanying drawings. As will become readily apparent to those Gilled in the art from the following description, there is shown and described an embodiment of this invention simply by way of the illustration of the best mode to carry out the invention. As will be realized, the invention is capable of other embodiments and its several details are capable of modifications and various obvious as, all without departing from the scope of the invention. Accordingly, the drawings and detailed description will be regarded as illustrative in nature and not as restrictive.